Using an elaborate poetic tool, the young man is expressing the uniqueness of his beloved.
This is another example in the Song where King Solomon is not being directly referred to but is rather a type of foil to the young man’s love for his bride. The comparison here is the exclusive love he has for the young woman as someone who is unique and who stands out in his eyes.
The three classes of women—queens, concubines, and virgins—represent all the options available to a king. Queens are primary wives with the most rights, concubines are secondary wives, and the Hebrew word almah, translated as virgins, stands for all those women who are marriageable and therefore available to the king.1
This verse is built on an ancient form of poetry called numerical parallelism. We see it in Proverbs in the form x, x+1; for instance, Under three [x] things the earth trembles; under four [x+1] it cannot bear up: a slave when he becomes a king, and a fool when he is filled with food; an unloved woman when she gets a husband, and a maidservant when she displaces her mistress
(Proverbs 30:21–23). The intention is not just that there are four things, but that there is a large number.
The young man’s complement, therefore, moves from sixty to eighty and then to countless young women. The point is that in his eyes the young woman is number one out of all women of all classes.2
Solomon took many wives. The Solomonic model of love is quantity over quality. Such a crowd of women can only be managed, not truly loved. The comparison is not just with Solomon personally, but with the general tendency for kings to multiply wives, often at the expense of others.3
This verse shows a contrast between the one who is intimately known and treasured as an individual by their lover, and others known only as members of a group or scarcely at all. The man who truly loves a woman knows that woman as a specific person, whose identity cannot simply be collapsed into her gender and is certainly not summed up only in her sexuality and in her sexual relationship with him.4
8 There are sixty queens and eighty concubines, and virgins without number.